A light emitting diode display device is a device that includes a plurality of light emitting diodes arranged as pixels on a printed circuit board. A light emitting diode (also referred to as an LED) has a structure including a light emitting diode chip and a package substrate. The light emitting diode chip includes a p-type semiconductor and an n-type semiconductor, which are pn-connected to an electrode on the package substrate. The light emitting diode chip and the electrode on the package substrate are connected by, for example, conduction wires. Gold or silver paste, gold wire, copper wire, or the like is used for the electrode and the conduction wires on the package substrate. A metal having a high reflectivity to visible light is used as a metal for the electrode and power line. Therefore, when visible light is incident on the light emitting diode from the outside, visible light is reflected from the electrode, the power line, and in some cases, a surface of the package substrate. This causes deterioration of the contrast of the light emitting diode display device.
Patent Document 1 (Japanese Patent No. 4299535) discloses a light emitting diode display device in which a black resist is formed on a package substrate, and reflection of visible light incident from the outside onto a light emitting diode is suppressed.
In the light emitting diode display device of Patent Document 1, an opening is provided in the black resist. Then, a light emitting diode chip is disposed in the opening of the black resist. A part of an electrode provided on a package substrate is exposed to the opening of the black resist. A conduction wire that supplies current to the light emitting diode chip is connected to the electrode exposed in the opening.
As described above, since the electrode of the light emitting diode display device of Patent Document 1 has a part which is not covered with the black resist, incident light from the outside is reflected at this part. Therefore, it is difficult to improve the contrast of the light emitting diode and the light emitting diode display device.